Polyvinyl oleate as a fat replacement

ABSTRACT

Polyvinyl alcohol fatty acid esters, notably unsaturated acid esters, comprise a new class of edible fat replacements. Polyvinyl oleate, prepared either by direct esterification of low molecular weight polyvinyl alcohol with oleic acid, oleic anhydride or oleyl chloride, by the transesterification between low molecular weight polyvinyl alcohol and methyl oleate, or by the interesterification between low molecular weight polyvinyl acetate and methyl oleate, is a preferred edible fat replacement.

BACKGROUND OF THE INVENTION

This invention relates to the use of polyvinyl alcohol fatty acidesters, notably unsaturated fatty acid esters, as fat replacements infood and pharmaceuticals. Polyvinyl oleate is a preferred compound inthis new class of edible fat replacements.

Since fats provide nine calories per gram compared to four calories pergram provided by protein or carbohydrates, major research efforts towardreduction of caloric intake for medical or health reasons have focusedon ways to produce food substances that provide the same functional andorganoleptic properties as fats, but not the calories. Analogues ofnatural triglyceride fat, sugar fatty acid polyesters and similarderivatives of other polyhydric compounds, neopentyl alcohol esters,esters of di- and tri-carboxylic acids, jojoba oil, silicone oils andvarious polysaccharides have been suggested for use as edible fatreplacements. (For recent reviews, see Hamm, D.J., 49 Food Sci. 419(1984), and Haumann, B.F., 63 J. Amer. Oil Chem. Soc. 278 (1986).)

In the selection, modification, and/or synthesis of low caloriereplacements of edible fats and oils, the polymeric fat replacements,for example, polysaccharides, have a great deal of structuralflexibility because of the inherent nature of polymers. Not only mayside chain fatty substituents attached to a chemical structure be variedto achieve different chemical and physical properties (as was the case,for example, with the hydrogenated, partially hydrogenated andunhydrogenated fatty acids condensed with sucrose in Eur. Pat. Ap. No.235,836 to Bodor and Page and in Eur. Pat. Ap. No. 236,288 to Bernhardtto make different sucrose polyesters), but the entire structure may beshortened or lengthened to make macromolecules of enormously differingfunctionality.

A number of branched and linear polysaccharides and lower molecularweight dextrins and amyloses have been suggested as fat replacements infoods. Polydextrose, a tasteless non-sweet low calorie bulking agentformed by the random polymerization of glucose with lesser amounts ofsorbitol and citric acid, has been used as a partial replacement for fat(and sugar) in a variety of common processed foods, including desserts(U.S. Pat. No. 4,626,441), dairy products (U.S. Pat. No. 4,631,196), andcrackers (U.S. Pat. No. 4,678,672). Polyglucoses and polymaltoses,prepared by the polycondensation of saccharides in the presence of apolycarboxylic acid catalyst, were synthesized and used in dieteticfoods in U.S. Pat. No. 3,876,794 to Rennhard and combined with dietaryfiber in U.S. Pat. No. 4,304,768 to Staub et al.

Converted starches (mostly from tapioca, corn, and potato starches),prepared by the chemical, thermal, or enzymatic degradation of starchmolecules to lower molecular weight fragments (including dextrins andamyloses), were disclosed as fat- or oil-replacements in foodstuffs inU.S. Pat. Nos. 3,962,465 and 3,986,890 to Richter et al., U.S. PatentNo. 4,247,568 to Carrington and Haleck, and U.S. Pat. No. 4,510,166 toLenchin et al. Modified high amylose starches have been employed as fatextenders in imitation cheeses (U.S. Pat. No. 4,504,509, U.S. Pat. No.4,608,265, and U.S. Pat. No. 4,695,475) and in batter coatings for bakedfood products that resemble fried foods (U.S. Pat. No. 4,504,509). Ananionic polysaccharide obtained from algae was disclosed with monoand/or disaccharides to extend fats in whippable emulsions in U.S. Pat.No. 3,944,680 to van Pelt et al.

Polyglycerol esters comprise another class of polymeric fatreplacements. Widely used as emulsifiers, polyglycerol fatty esters arewax-like solids which may be used with hydrophilic colloids to formcompositions oleaginous in appearance and texture, but containingsubstantially no fat. Linear and cyclic polyglycerols of different chainlengths have been prepared for consumption in food (U.S. Pat. No.3,968,169), and substituted with a range of fatty acid residues (U.S.Pat. No. 3,637,774) for use in margarine, imitation butter, cheesespreads, dips, puddings, icings, salad dressings, sauces, and frozendesserts, including ice cream and sherbet (U.S. Pat. Nos. 3,637,774 and4,046,874).

Though great variations in chain length and structure are possible withthe currently available polymeric fat substitutes, most have thedisadvantage of being at least partially, if not totally, digestible.(See Haumann, supra, pp. 278-280, for a discussion of polysaccharides,and Babayan, V.K., 41 J. Amer. Oil Chem. Soc. 434 (1963), forpolyglycerol esters.) In addition, polymerization reactions are hard tocontrol. The direct free radical polymerization of vinyl esters ofunsaturated fatty acids, for example, do not form linear polymers, butpolycondense to form cross-linked products (Seymour, R.B., and Carraher,C.E., Polymer Chemistry, Marcel Dekker, New York, 1988, chapter 9).

By the same token, degradation reactions are hard to control. Thus,close attention must be made to the conditions under which starches aredegraded to form dextrins and sugars (U.S. Pat. No. 4,510,166).Homogeneous products are difficult to achieve, and vary greatly with thestarting material used. Even if the starting material were a purecompound, which most natural products are not, the sugar moieties makingup polysaccharide chains have myriad functional groups that can react,and geometric and optical isomerism further complicates condensationreactions. (In the esterification of a single sucrose molecule with anexcess of fatty acid, for instance, the eight hydroxyl groups can reactto form 255 different sucrose esters if all isomers are counted; seeWeiss, T.J. et al., 48 J. Amer. Oil Chem Soc. 145 (1971).)

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a simple polymericfat replacement for food compositions which is free from theabove-described disadvantages. Heterogeneity problems resulting from thepolymerization or degradation of polysaccharides and polyglycerols toform complex mixtures of macromolecules are avoided by using a simplepolymeric backbone to which fatty substituents can be attached.Synthetic fats with the different properties (rheology, viscosity, andso forth) needed for different culinary applications can be formulatedby varying the degree of substitution and the chain length of thepolymer.

It has now been found that relatively low molecular weight polyvinylalcohol esterified with fatty acids can be used as an edible fatreplacement for part or all of the fat in food compositions. Moreparticularly, it has been found that unsaturated fatty acid esters ofpolyvinyl alcohol are especially useful as fat replacements in food, andthat polyvinyl oleate is a preferred compound.

DETAILED DESCRIPTION OF THE INVENTION

Polyvinyl alcohol (--CH₂ --CHOH--)_(n) is apparently the simplestpossible water-soluble polymer. (See recent reviews in Dunn, A.S., 1980Chem. & Ind. (London), 801-806 and Leeds, M., in the Kirk-OthmerEncyclopedia of Chemical Technology, 2nd ed., vol. 21,Wiley-Interscience, N.Y., 1970, pp. 353-368. Most of its uses involveextrusion of the resin or its application as a surface coating. It hasbeen employed in films, adhesives and binders, and in the treatment oftextiles and paper.

Polyvinyl alcohol undergoes chemical reactions very similar to those oflow molecular weight aliphatic alcohols. For example, it reacts withacid chlorides or anhydrides to form esters. In many instances, it ispossible to obtain a completely new resin by reacting all of thehydroxyl groups. Even with lesser degrees of substitution, theproperties of the resin may be considerably altered, while retaining, ifdesired, the water solubility. Further interesting property variationscan be achieved by using partially hydrolyzed polyvinyl alcohol or byvarying the chain length of the polymer.

Polymeric synthetic drying "oils" for use in the surface coatingsindustry can be prepared by reaction of polyvinyl alcohol with longchain unsaturated fatty acids (Leeds, M., supra at 358). Polyvinyloleate was among the polyvinyl alcohol esters synthesized for this use(U.S. Pat. No. 2,601,561 to Schertz; Rheineck, A.E., 28 J. Am. Oil Chem.Soc. 456 (1951); and Balakrishna, R.S. et al., 16 Paintindia 20 (1967)).However, among the esters made, polyvinyl oleate was a poor drying oil.When used in a varnish, it did not exhibit desirable properties, e.g.,it did not develop early hardness (Rheineck, A.E., supra at 458). A filmof the ester took a long time drying, and even then remained tacky aftertwo months (Balakrishna, et al.. supra at 21)

The polyvinyl alcohols used to make these unsuccessful polyvinyl oleatesynthetic drying oils were, relatively, medium chain length resins. M.Leeds gives molecular weights of parent polyvinyl acetates as rangingfrom 10,000 to 400,000 (Table 3, supra at 356). In the examples of U.S.Pat. No. 2,601,561, the polymeric alcohols employed were molecularweight 14,000 (Examples I-VI and VIII) or 52,000 (Example VII). R.S.Balakrishna, et al. used polyvinyl alcohol having a molecular weight30,000 to 35,000 (supra at 20).

In the practice of the present invention, on the other hand, aconsiderably lower molecular weight polyvinyl alcohol is esterified withfatty acids, preferably unsaturated fatty acids such as oleic acid, touse as an edible fat replacement. The polymeric size will range betweenmolecular weight 500 and 8000, preferably between 1000 and 5000.

The term "polyvinyl alcohol" as used herein refers to a polymer preparedfrom polyvinyl acetate by replacement of the acetates with hydroxylgroups, and may contain residual acetyl groups. In the practice of thisinvention, some residual acetyl groups are preferred. In general,polyvinyl alcohol acetylated to 25% esterification is preferred overpolyvinyl alcohol substantially free of acetyl groups.

The term "fatty acids" used here means organic fatty acids containingfour to thirty carbons, and may be synthetic or natural, saturated orunsaturated, with straight or branched chains. Preferred fatty acidshave from 10 to 22 carbons. Examples of fatty acids that can be used inthis invention are butyric, caproic, caprylic, pelargonic, capric,lauric, myristic, palmitic, stearic, arachidic, behenic, oleic,linoleic, linolenic, eleostearic, and arachidonic acids. Mixtures offatty acids may also be used, such as those obtained fromnon-hydrogenated or hydrogenated soybean, safflower, sunflower, sesame,peanut, corn, olive, rice bran, canola, babassu nut, coconut, palmkernel, cottonseed, or palm oils.

In this invention, unsaturated fatty acids are preferred. The term"unsaturated fatty acid" as used here means any unsaturated fatty acidcontaining at least 8, and preferably from 14 to 22, carbon atoms. Theunsaturated fatty acids must contain at least one alkene linkage and maycontain two or more alkene groups in any position in the hydrocarbonchain, and the unsaturation may or may not be present as a conjugatedsystem of double bonds. A suitable acid for this purpose is oleic acid.Alternatively, mixtures containing oleic and/or other unsaturated acids,such as that obtained from cottonseed, peanut, olive, palm, sunflower,sesame, safflower, rice bran, soybean, or corn oil may be used.

The term "fatty acid derivative" as used herein means a derivative otherthan an ester, for example, a fatty acid, a fatty acid chloride, or afatty acid anhydride.

The term "fatty acid ester" as used herein means the methyl, ethyl,propyl, butyl, or pentyl ester of a fatty acid, and any geometric oroptical isomer thereof. In the preferred embodiment, the methyl or ethylester of an unsaturated fatty acid is used.

A solvent may be employed. The term "solvent" used in the descriptionand claims means any material that is liquid at the synthesis reactiontemperature and pressure and will dissolve, suspend or hold thereactants in the reaction mixture in an amount effective to expeditecontact for the desired esterification, interesterification ortransesterification to occur.

In the practice of the present invention, polyvinyl alcohol may becondensed with a fatty acid, a fatty acid chloride, or a fatty acidanhydride; in the preferred embodiment, the fatty acid or fatty acidderivative is unsaturated. The total amount of fatty acid, acidchloride, or anhydride present in the reaction mixture can be a maximumthat theoretically will react to completely esterify all the freehydroxyls of the polyvinyl alcohol. Thus, the total amount of fatty acidor acid chloride or anhydride present will be one mole for each mole offree hydroxyl moieties available on the polyvinyl alcohol reactant.However, best results are achieved by using an excess of fatty acid,acid chloride or anhydride. Typically, a thirty percent excess isemployed.

In an alternate practice of the present invention, polyvinyl alcohol maybe transesterified with a fatty acid ester, preferably an unsaturatedfatty acid ester. Theoretically, the total amount of fatty acid esterpresent in the reaction mixture can be a maximum that theoretically willreact to completely transesterify all the hydroxyls of the polyvinylalcohol reactant. However, best results are achieved by using an excessof fatty acid ester over the theoretical stoichoimetric amount required.Typically, a fifteen percent excess is used.

In another alternate practice of the present invention, polyvinylacetate may be interesterified with a fatty acid ester, preferably anunsaturated fatty acid ester. Theoretically, the total amount of fattyacid ester present in the reaction mixture can be a maximum that willreact to completely interesterify all the acetate groups of thepolyvinyl reactant.

The transesterification and interesterification reactions are carriedout in the presence of a catalyst, such as, for example, sodium. Asodium/potassium alloy can also be used.

According to a preferred embodiment of the present invention, thepolyvinyl alcohol is dissolved in the fatty acid, the acid chloride, oranhydride. Alternatively, the polyvinyl acetate is dissolved in thefatty acid ester and a catalyst is added to the mixture. The reactionmixture in either case may be warmed at reflux and stirred to speed thereaction. The length of reaction time varies with the reactionconditions and may require several hours.

The polyvinyl esters of this invention may be incorporated either alone,or in combination with another fat and/or fat mimetic, into any foodcomposition or used in conjunction with any edible material. The term"edible material" is broad and includes anything edible. Representativeof edible materials which can contain the polyvinyl esters of thisinvention in full or partial replacement of natural fat are: frozendesserts, e.g., sherbet, ice cream, ices, or milk shakes; puddings andpie fillings; margarine substitutes or blends; flavored bread or biscuitspreads; mayonnaise; salad dressings; filled dairy products such asfilled cream or filled milk; dairy or non-dairy cheese spreads; coffeelighteners, liquid and dried; flavored dips; frying fats and oils;reformed and comminuted meats; meat substitutes or extenders; whippedtoppings; compound coatings; frostings and fillings; cocoa butterreplacements or blends; candy, especially fatty candies such as thosecontaining peanut butter or chocolate; chewing gum; bakery products,e.g., cakes, breads, rolls, pastries, cookies, biscuits, and savorycrackers; mixes or ingredient premixes for any of these; as well asflavor, nutrient, drug or functional additive delivery systems.

EXAMPLES

The following examples detail three methods of preparing polyvinyl fattyacid esters in accordance with the present invention, an in vitroscreening test for lipase digestibility of the compounds, and somecompound uses in food compositions. It is to be understood that theseexamples are merely illustrative and are not to be construed as beinglimitative. In the chemical syntheses, the biochemical screenings, andthe food composition recipes, all percentages given are weightpercentages, and are based on the weight at the particular stage ofprocessing described.

Example 1

Polyvinyl oleate for use in food compositions is synthesized frompolyvinyl alcohol in this example.

A reaction flask is charged with 1.25 grams polyvinyl alcohol powder(0.00063 moles of 75% hydrolyzed polymer, approximately 2000 molecularweight). To the flask is added 15 grams oleic anhydride. The flask isstirred and heated to reflux at 218° C. for seven hours. After thecontents of the flask cools to room temperature, the reaction product isdissolved in 200 mL toluene. A hundred mL water is added to this mixtureand separated using a separatory funnel. The water layer is removed andtested with litmus. More water is added in 100 mL aliquots, and thisprocedure is repeated until the water layer is neutral to litmus paper.This requires between 5 to 10 washings.

The remaining toluene layer is transferred to a beaker and heated overmoderate heat on a hot plate to evaporate the toluene. The beaker isthen placed in a vacuum oven of 105° C. for twenty-four hours.

Example 2

In this example, polyvinyl oleate for use in food compositions issynthesized from polyvinyl acetate.

A reaction flask is charged with 25 grams polyvinyl acetate resin(0.00357 moles of Rhodopas RB-1, a resin that meets the chemicalidentity standards listed in the Food Additive Regulation 21 C.F.R.172.615, and has a molecular weight of approximately 7000). To the flaskis added 100 grams 99% methyl oleate and 1.74 grams sodium. The flask isstirred and heated to reflux at 216° C.

Example 3

This example describes an alternate polyvinyl oleate synthesis.

A reaction flask equipped with a magnetic stirrer, a thermometer, adropping funnel, a nitrogen purge, and a reflux condenser is chargedwith 10 grams polyvinyl alcohol (molecular weight 2000, 75% hydrolyzed)and 115.68 grams phenol. The mixture is stirred, heated, and purged withnitrogen throughout the dissolution. At about 90° C., the polyvinylalcohol begins to become soluble in the phenol, forming a clear yellowsolution. After two hours between 100° and 130° C., practically all thepolyvinyl alcohol is in solution.

The reflux condenser is then changed to a distillation apparatus, and48.2 grams oleic acid is slowly added dropwise through the droppingfunnel as phenol is distilled off over the course of about three hours.(Phenol which occasionally crystallizes in the condenser is melted witha heat gun.) During the course of the reaction, the temperature risesfrom 185° to 250° C. The mixture is left overnight.

The mixture is then reheated to 235° C. for two and a half hours undervacuum. The mixture changes from yellow to brown. About 115 grams ofcrude reaction product is recovered and further purified by step-wiseseparatory funnel extraction with three 120-mL aliquots of methanol. The(top) methanol layers extract color and are decanted and discarded,leaving a mustard-colored product which is vacuum dried to a clear brownviscous oil product.

Example 4

This example outlines the procedure for estimating the in vitrodigestibility of the polyvinyl esters of this invention.

Preparation of Reagents and Materials

1. Buffer: A pH 7.1 phosphate buffer is prepared by dissolving 6.8 g.KH₂ PO₄ in 1 L. of millipore filtered water (to yield 0.05 M phosphate).Fifty mg. Ca(NO₃)₂ and 5.0 g. cholic acid (Na salt, an ox bile isolatefrom Sigma) are added to give 300 microM Ca⁺⁺ and 0.5 % cholic acid in0.05 M phosphate. The pH is adjusted to approximately 7.1 with solidNaOH. Several drops of Baker "Resi-analyzed" toluene are added toprevent bacterial growth during storage at 3-5° C.

2. Lipase: About 15 mg./mL commercial porcine pancreatic lipase fromU.S. Biochemical Corporation is dissolved in buffer.

3. Substrates and Standards: A 1.0 mL volumetric flask is charged withan amount of lipid substrate (test substance or standard) calculated togive a concentration of 200 nanomoles per microliter in Baker"Resi-analyzed" toluene. (The proper concentration may be approximatedby doubling the molecular weight of the lipid in question, dividing by10, and diluting to the mark; this yields about 200 nanomoles permicroliter.) This preparation affords the substrate to be used in thehydrolysis reactions. Fatty acids and glyceride standards from Nu Chekor Sigma are prepared for elution on TLC plates (prewashed with 1:1chloroform/methanol) by diluting the substrate solution with 10:1toluene (1 part substrate plus 9 parts toluene) in septum vials.

Procedure

In a 25 mL Erlenmeyer, emulsify 20 mL buffer (at room temperature) and40 microliters of substrate using an ultrasonic disrupter at a microtipmaximum setting for approximately 10 seconds. This results in a 0.4micromole/milliliter emulsion. Place in a 37° C. water bath and stirvigorously. After temperature equilibration, add 40 microliters ofenzyme solution and start timing. Remove 5.0 mL aliquots at convenienttime intervals for analysis. To establish a standard curve for triolein,for example, aliquots are taken at 10, 20, 30 and 40 minutes. A zerotime control should be run for all test compounds. Add the aliquot to a15 mL glass centrifuge tube containing a drop of concentrated HCl. Addapproximately 3 mL of a 2:1 mixture of CHCl₃ : CH₃ OH and shakevigorously. Centrifuge at approximately 5000 rpm for about 5 minutes andtransfer the bottom layer with a Pasteur pipet to a 5 mL septum vial.Repeat the extraction step once and combine the two bottom layers.Evaporate the solvent in nitrogen gas. After about half of the solventis removed, add an equivalent volume absolute ethanol and continueevaporation in a nitrogen stream until dryness is achieved. Samples maybe warmed with a heat gun to facilitate drying.

When the samples are dry, add exactly 200 microliters of toluenecontaining 10% DMSO, cap tightly, and spot TLC plate with 2.0microliters per channel. (If 100% extraction efficiency of a zero timecontrol, this amounts to 20 nanomoles of substrate spotted on theplate.) Develop with a suitable solvent system, such as, for example,hexane: ethyl ether: acetic acid in a ratio of 60:40:1. After 15 cmelution, dry plate with a heat gun and determine amounts of startingsubstrate and products of hydrolysis by scanning 10 to 20 nanomoles perchannel at a wavelength of 190 nm using the CAMAG TLC Scanner IIdensitometer equipped with a Spectra Physics 4270 integrator andcomparing with controls run at the same time.

Results

Using this procedure with polyvinyl oleate prepared in Example 3, nohydrolysis is observed after three hours contact with pancreatic lipase.Using a triglyceride control, triolein is substantially hydrolyzed in 10minutes with this enzyme system.

Example 5

Polyvinyl oleate prepared in Example 3 is used in a cookie recipe inthis example.

The cookie dough is prepared by creaming together 23.11 grams finegranulated sucrose, 0.37 grams salt, 0.44 grams sodium bicarbonate, and11.38 grams polyvinyl oleate. At this stage, no "foam" appears as withsolid shortening during creaming. To this blend is added 3.74 gramsdistilled water and 5.87 grams 5.93% (wt/wt) dextrose solution, and then39.10 grams flour. The dough is very tacky, and may be extruded orrolled out and cut before baking in the usual manner (e.g., at 400°Fahrenheit for 10 minutes). The tops of the cookies crack during baking.

Example 6

Polyvinyl oleate prepared in Example 3 is used in a sprayed crackerrecipe in this example.

A dough prepared from 100 parts flour, 5 parts sugar, 1.5 parts malt,7.5 parts of the polyvinyl oleate prepared in Example 3, 1 part salt,0.9 parts sodium bicarbonate, 2.5 parts non-fat dry milk, 2.5 parts highfructose corn syrup, 0.75 parts monocalcium phosphate, and 28 partswater is sheeted, stamped, sprayed with polyvinyl oleate from Example 3,and baked to produce a cracker product.

Example 7

Polyvinyl oleate prepared in Example 3 is used as a frying oil in thisexample.

Standard packaged precut and frozen "French fried" potatoes are droppedinto preheated polyvinyl oleate and fried at 325° to 375° F. for 8 to 10minutes, or until golden.

The above descriptions are for the purpose of disclosing to a personskilled in the art how to practice the present invention. These are notintended to detail all the obvious modifications and variations of theinvention which will become apparent upon reading. However, applicantsdo intend to include all such obvious modifications and variationswithin the scope of their invention which is defined by the followingclaims.

What is claimed is:
 1. A food composition comprising as an edible fatcompound, molecular weight 1000 to 5000 polyvinyl alcohol esterifiedwith fatty acids.
 2. The composition according to claim 1 wherein thefatty acids comprise C₄ to C₃₀ fatty acids.
 3. The composition accordingto claim 1 wherein the fatty acids are selected from the groupconsisting of butyric, caproic, caprylic, pelargonic, capric, lauric,myristic, palmitic, stearic, arachidic, behenic, oleic, linoleic,linolenic, eleostearic, and arachidonic acids, and mixtures thereof. 4.The compound according to claim 1 wherein the fatty acids are derivedfrom non-hydrogenated or hydrogenated oils selected from the groupconsisting of soybean, safflower, sunflower, sesame, peanut, corn,olive, rice bran, canola, babassu nut, coconut, palm kernel, cottonseed,and palm oils.
 5. The composition according to claim 4 wherein said oilis selected from the group consisting of cottonseed, peanut, olive palmsunflower, sesame, safflower, rice bran, soybean, and corn oil.
 6. Thecomposition according to claim 1 wherein the fatty acids compriseunsaturated fatty acids.
 7. The composition according to claim 6 whereinthe fatty acids comprise C₁₄ to C₂₂ fatty acids.
 8. The compositionaccording to claim 6 wherein the unsaturated fatty acid is oleic acid.9. The composition of claim 1 wherein said food composition is a cookie.10. The composition of claim 1 wherein said food composition is acracker.
 11. The composition of claim 1 wherein said food composition isa frying oil.
 12. The method of preparing a reduced calorie foodcomposition which comprises formulating said composition with molecularweight 1000 to 5000 polyvinyl alcohol esterified with fatty acids. 13.The method according to claim 12 wherein said fatty acids comprise C₄ toC₃₀ fatty acids.
 14. The method according to claim 12 wherein the fattyacids are selected from the group consisting of butyric, caproic,caprylic, pelargonic, capric, lauric, myristic, palmitic, stearic,arachidic, behenic, oleic, linoleic, linolenic, eleostearic, andarachidonic acids, and mixtures thereof.
 15. The method according toclaim 12 wherein the fatty acids are derived from non-hydrogenated orhydrogenated oils selected from the group consisting of soybean,safflower, sunflower, sesame, peanut, corn, olive, rice bran, canola,babassu nut, coconut, palm kernel, cottonseed, and palm oils.
 16. Themethod according to claim 12 wherein the fatty acids compriseunsaturated fatty acids.
 17. The method according to claim 16 whereinthe fatty acids comprise C₁₄ to C₂₂ fatty acids.
 18. The methodaccording to claim 12 wherein the fatty acid ester is polyvinyl oleate.19. The method according to claim 12 wherein said food composition is acookie.
 20. The method according to claim 12 wherein said foodcomposition is a cracker.
 21. The method according to claim 12 whereinsaid food composition is a frying oil.
 22. In a food composition theimprovement wherein at least a portion of the digestible fat ingredientis replaced by an unsaturated fatty acid ester of molecular weight 1000to 5000 polyvinyl alcohol to produce a reduced calorie product.
 23. Thecomposition of claim 22 wherein said food composition is a bakeryproduct.